Modeling, simulation and control of an electric diwheel

Abstract

A diwheel is a novel vehicle made up of an inner frame which is encompassed and supported by two large coaxially aligned wheels. The inner frame is typically supported by a common axle or roller type idler wheels and as a result, is free to oscillate back and forth relative to the outer wheels. The outer wheels are driven from the inner frame and forward motion is achieved through a reaction torque generated by the eccentricity of the centre of gravity (CoG) of the inner frame. During operation, diwheels experience slosh (when the inner frame oscillates) and tumbling (when the inner frame completes a revolution). In this paper the dynamics of a generic diwheel are derived. Three control strategies are then proposed; slosh control, swing-up control and inversion control. Finally, simulations are conducted and compared with experimental results all performed on a diwheel built at the University of Adelaide.